Today the MS Exchange Team released the ExPDA tool, or Exchange Server Pre-Deployment Analyzer. This tool is meant to scan and analyse your current e-mail enviroment for possible. ExPDA can also be used as an decisionmaking tool, helping you through the process of implementing Exchange 2010.
ExPDA is based on ExBPA – Exchange Best Practice Analyzer – but looks more at the complete topology than at the system level. Amongst many other things, it scans current Exchange (2003, 2007) systems and domain controllers/gc’s for required patchlevels, connectors and domains and forests for required modes in order to implement Exchange Server 2010.